Related Experiment Videos
Repeated nicotine exposure enhances responding with conditioned reinforcement
Peter Olausson1, J David Jentsch, Jane R Taylor
1Department of Psychiatry, Laboratory of Molecular Psychiatry, Yale University, 34 Park Street, New Haven, CT 06508, USA.
Psychopharmacology
|January 17, 2004
Summary
Repeated nicotine exposure enhances conditioned reinforcement, increasing cue control over behavior. This effect is further amplified by amphetamine, suggesting long-lasting neuroadaptations relevant to addiction.
Area of Science:
- Neuroscience
- Behavioral Pharmacology
- Addiction Research
Background:
- Conditioned reinforcement explains how cues associated with rewards, like drugs, can drive behavior.
- Clinical observations suggest conditioned reinforcement is crucial for smoking, but nicotine's long-term effects on this are unclear.
Purpose of the Study:
- To examine how repeated nicotine exposure affects conditioned reinforcement.
- To investigate if nicotine pretreatment potentiates conditioned reinforcement when combined with amphetamine in the nucleus accumbens (NAc).
Main Methods:
- Rats received daily nicotine or saline injections for 15 days, followed by a withdrawal period.
- Animals were trained to associate auditory and visual cues with water reinforcement.
- Conditioned reinforcement responding was tested, with some groups receiving intra-NAc amphetamine infusions.
Main Results:
- Prior repeated nicotine exposure significantly enhanced responding maintained by conditioned reinforcement.
- Nicotine pretreatment also amplified the potentiation of conditioned reinforcement by amphetamine infusions into the NAc.
Conclusions:
- Repeated nicotine exposure strengthens the influence of conditioned reinforcers on behavior.
- These findings suggest nicotine-induced neuroadaptations in dopamine pathways contribute to persistent addictive behaviors.